Close the fourth side
Draw lines between dots to claim boxes. Completing a box earns another turn, making chains the key to a comeback.


The pen-and-paper classic, digitized. Draw a line, close the fourth side of a box and it's yours — go again and chain them for a run that can take half the board. Board sizes from 3×3 up to a custom 20×20, against CPU or a friend.
3×3 to 20×20 boards, CPU or local play
Undo and in-progress game persistence
Tracks games won, boxes closed, longest chain